JP2009162492A - Inspection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine quality of a work without any misrecognition even if the work is held by a holding mechanism such as a holding section. <P>SOLUTION: In an inspection apparatus 1, an illumination section 3 having a ring-like light source section 33 for irradiating the work 2 with light and a photographing section 4 for photographing the work 2 are provided, the holding section 5 for holding the work 2 is arranged fixedly or movably between the illumination section 3 and the photographing section 4, and the photographing section 4 is arranged at a position deviating from that in the irradiation direction of light applied to the work 2 from the light source section 33 of the illumination section 3. Then, when there are indeterminate objects including a foreign matter in the work 2, the optical path of light applied to the work 2 from the light source section 33 is changed by indeterminate objects including foreign matters and the light is photographed by the photographing section 4. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an inspection apparatus that inspects a workpiece to be inspected.

Conventionally, when visual inspection of a workpiece to be inspected is performed, the quality of the workpiece is determined visually. For this reason, the standard for visual quality judgment changes depending on the skill level of the worker, and the quality judgment of the workpiece varies.
In view of this, an inspection apparatus that uses a photograph of a workpiece and analyzes the photographed image to determine whether the workpiece is good or not is now being used due to advances in image processing technology (see, for example, Patent Document 1).

  The inspection apparatus described in Patent Document 1 is an apparatus that inspects whether there is a scratch, dust, dirt, or the like on the work surface, and illuminates and reflects light on the work surface and reflects the light reflected by the photographing unit. Shoot.

Specifically, according to the inspection apparatus described in Patent Document 1, light is reflected at a site where there is no scratch or the like on the work surface, and light is irregularly reflected at a site where there is a scratch or the like. Therefore, when a workpiece is photographed under constant illumination, the surface of the workpiece is photographed with different brightness on the part with scratches and the part without scratches, and the quality of the workpiece is judged based on the difference in brightness. I do.
JP 2005-201880 A

  By the way, in the inspection apparatus described in Patent Document 1, since the light is reflected and the reflected light is photographed by the photographing unit, the photographing unit retains and fixes not only the reflected light on the workpiece surface but also the workpiece. The light reflected at is also photographed.

  For this reason, the light reflected by the holding unit also affects the light quantity for determining the quality of the work, and the light reflected by the holding unit is erroneously recognized as light that is irregularly reflected on the work surface.

  Therefore, in order to solve the above-described problem, an object of the present invention is to provide an inspection apparatus that performs a quality determination of a workpiece without erroneous recognition even when the workpiece is held by a holding mechanism such as a holding unit. .

  In order to achieve the above object, an inspection apparatus according to the present invention is an inspection apparatus that inspects a workpiece to be inspected, an illumination unit having an annular light source unit that illuminates the workpiece, and an imaging unit that images the workpiece. The holding unit that holds the workpiece is arranged so as to be fixed or movable between the illumination unit and the imaging unit, and deviates from the irradiation direction of the light irradiated to the workpiece from the light source unit of the illumination unit. When the photographing unit is arranged at a position and there is an uncertain object (including a foreign object) on the workpiece, the light path of the light irradiated to the workpiece from the light source unit is changed by the uncertain object (including the foreign object). The image is taken by the photographing unit.

  According to the present invention, it is possible to determine whether or not a workpiece is good without erroneous recognition even when the workpiece is held by a holding mechanism such as a holding unit. In particular, according to the present invention, since the photographing unit and the illumination unit are arranged via the work held by the holding unit, the same direction with respect to the work with respect to the work held by the holding unit. The photographing unit and the illumination unit are not provided at the same side position. Therefore, the reflected light of the light irradiated on the work and the reflected light reflected by the holding part that holds the work are not photographed by the photographing part, and all foreign matters (scratches and It becomes possible to discover uncertain things including garbage and stains). Further, according to the present invention, since the photographing unit and the illumination unit are not provided in the same direction (position on the same side) with respect to the workpiece on the basis of the workpiece held by the holding unit, the illumination unit It is possible to prevent the holding portion from shining white by the illumination from the light, and to prevent erroneous recognition of the holding portion as a foreign matter due to white light emission.

  The said structure WHEREIN: The said imaging | photography part is good also as imaging | photography of the light of a wavelength shorter than red.

  In this case, it is possible to clearly capture the foreign object by the imaging unit while suppressing the blurring of the outline of the foreign object in the captured image by the imaging unit due to the long wavelength such as red. .

  In the above configuration, when an uncertain object is present in the workpiece and the uncertain object has a major axis of 20 μm or more, the indeterminate object may be determined as a foreign object.

  In this case, it is possible to improve the accuracy of the foreign object determination by determining the foreign object based on the size of the indeterminate object rather than determining the foreign object using pixels.

  The said light source part may irradiate the directional light with an angle with respect to the workpiece | work hold | maintained at the said holding | maintenance part in the said structure.

  In this case, the light from the illuminating unit does not directly irradiate the photographing unit, and even if light is applied to the workpiece, the workpiece itself is not illuminated. Therefore, only when an uncertain object including a foreign object exists on the workpiece, the uncertain object including the foreign object can be illuminated, and the foreign object can be easily confirmed.

  In the above configuration, the illumination unit is formed of a cylindrical body having a through-hole, and is disposed at a position opposite to the side on which the imaging unit is disposed of the illumination unit with an inclination with respect to the workpiece. A prevention plate may be provided, and the imaging unit and the prevention plate may face each other through the through hole.

  In this case, it is possible to prevent the light that is irradiated to the work and reflected by the work from being photographed by the photographing unit.

  The said structure WHEREIN: A blackboard may be sufficient as the said prevention board.

  In this case, the shooting area (field of view) in the shooting unit can be made black.

  In the above-described configuration, the photographing by the photographing unit may be monochrome photographing, and the photographing unit may be intended for photographing single wavelength light.

  In this case, even in monochrome photography, it becomes possible to clarify the dimensions of an uncertain object including a foreign object, and it is possible to reduce the equipment cost.

  The said structure WHEREIN: The said light source part may consist of LED.

  In this case, the illumination life is long, there is no decrease in output, and stable illumination can be performed.

  In the above configuration, the light source unit is made of halogen, and a filter that sorts (filters) light from the light source into light having a wavelength shorter than red is provided in at least one of the illumination unit and the imaging unit. May be.

  In this case, the outer shape of an indeterminate object including a foreign substance can be clarified even with a halogen that emits visible light. Further, it is possible to clearly capture the foreign object by the imaging unit by suppressing the blurring of the foreign object outline of the captured image by the imaging unit due to the long wavelength of visible light such as red. It becomes possible.

  The said structure WHEREIN: The said illumination part may be provided with the diffusion filter which diffuses light irradiation in the irradiation direction front surface of the light irradiated from the said light source part.

  In this case, since the diffusion filter is provided, if there is an uncertain object including foreign matter on the work, glare due to light irradiation to the uncertain object can be suppressed. It becomes possible to clarify the outer shape (outline).

  According to the inspection apparatus according to the present invention, it is possible to determine whether or not a workpiece is good without erroneous recognition even when the workpiece is held by a holding mechanism such as a holding section.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, a case where the present invention is applied to a filter that is an optical component as a workpiece to be inspected is shown.

  The inspection apparatus 1 according to the present embodiment adopts a transmission method, and inspects whether or not there is a foreign object on the workpiece to be inspected.

  Specifically, as shown in FIG. 1, the inspection apparatus 1 includes an illumination unit 3 that illuminates the workpiece 2, an imaging unit 4 that photographs the workpiece 2, and a holding unit 5 that holds the workpiece 2. An information processing device 6 is connected to the imaging unit 4 by wire.

  As shown in FIGS. 1 and 2, the illuminating unit 3 is formed of a cylindrical body having a through hole 31, and the upper part of the inner wall surface 32 of the through hole 31 in the plan view has a gradient toward the lower part of the plan view. It is formed into a tapered shape. In the upper part of the tapered inner wall surface 32 in plan view, a light source part 33 having a ring shape in plan view is provided, and the light source part 33 is configured by arranging a plurality of LEDs in a plurality of rows in two upper and lower stages. Further, each of the plurality of LEDs irradiates light in a direction perpendicular to the taper-formed inclination angle (irradiation in the direction of the one-dot chain line in FIG. 1). That is, the light source unit 33 irradiates the workpiece 2 held by the holding unit 5 with light having a directivity (in the direction of the one-dot chain line in FIG. 1) having an angle.

  In addition, the illumination unit 3 diffuses the light irradiation so as to face the front surface of the inner wall surface 32 formed in a tapered shape in front of the light irradiation direction from the light source unit 33. A diffusion filter 34 is provided (attached). The diffusion filter 34 is formed of a disc-like body having an outer periphery in plan view and an inner periphery in plan view. Thus, by attaching the diffusion filter 34, when there is an uncertain object including foreign matter on the workpiece 2, glare due to light irradiation to the uncertain object can be suppressed. The outline (outline) of a simple object can be made clear.

  The photographing unit 4 is provided with a camera that performs monochrome photographing, and this camera uses a seamless zoom lens. The photographing unit 4 is intended for photographing light having a wavelength shorter than that of red, and particularly desirably photographing single-wavelength light. In this embodiment, blue single-wavelength light is taken as an object to be photographed.

  The holding unit 5 is fixed to the inspection apparatus 1 and is disposed between the illumination unit 3 and the imaging unit 4. The holding unit 5 is configured to fix and hold the workpiece 2 by pressing the side surface of the workpiece 2.

  In the information processing device 6, not only the image captured by the imaging unit 4 is arithmetically processed to check whether or not there is a foreign object on the workpiece 2, but something (indeterminate) is reflected on the workpiece 2. If it is determined that the uncertain object is larger than a preset dimension, and if the result of the measurement is a predetermined dimension or more, the uncertain object is determined as a foreign object The workpiece 2 on which foreign matter is adhered or formed is determined as a defective product. In this embodiment, when the standard dimension for determining a foreign object is 20 μm or more in the major axis and the major dimension is measured to be 20 μm or more, the indeterminate object is identified as a foreign substance.

  In the inspection apparatus 1 described above, the work 2 held by the holding unit 5 is disposed between the illumination unit 3 and the imaging unit 4. Further, the photographing unit 4 is arranged at a position deviating from the irradiation direction of the light irradiated to the work 2 from the light source unit 33 of the illumination unit 3.

  Further, the inspection apparatus 1 is arranged at an inclination with respect to the holding unit 5 holding the workpiece 2 below the illumination unit 3 in plan view (specifically, inclined about 45 degrees in this embodiment). A prevention plate 7 is provided. That is, the prevention plate 7 is provided at a position on the opposite side to the side where the photographing unit 4 of the illumination unit 3 is disposed. The prevention plate 7 is made of a glossy blackboard and faces the photographing unit 4 through the through hole 31 of the illumination unit 3. According to the prevention plate 7, the light reflected by the work 2 and the holding unit 5 that holds the work 2 (the two-dot chain line direction in FIG. 1) is guided (reflected) in a direction other than the photographing unit 4.

  In the inspection apparatus 1 having the above-described configuration, when there is an uncertain object including foreign matter on the workpiece 2 held by the holding unit 5, the light irradiated (illuminated) from the light source unit 33 to the workpiece 2 is not including the foreign matter. The optical path is changed by a definite object and photographed by the photographing unit 4, and other light is not reflected on the camera of the photographing unit 4 without irradiating the photographing unit 4. The change of the optical path here means that light is refracted or reflected by an uncertain object including a foreign substance.

  In the inspection apparatus 1 described above, the shortest distance from the photographing unit 4 (the lens end surface of the camera) to the work is set to 90 mm, and the shortest distance from the work 2 to the light source unit 33 of the illumination unit 3 is set to 30 mm. Yes. This setting is a setting in which the camera of the photographing unit 4 does not exist in the illumination direction (emission direction) of light from the light source unit 33 of the illumination unit 3 through the work 2 having no uncertain object including foreign matter. Numerical values are limited to the present embodiment, and are not limited to this setting. In other words, when the work 2 having no uncertain object including foreign matter is illuminated with light from the light source unit 33 of the illumination unit 3, the setting may be made so that light does not enter the camera of the photographing unit 4.

  As described above, according to the inspection apparatus 1 according to the present embodiment, even if the workpiece 2 is held by a holding mechanism such as the holding unit 5, it is possible to determine whether the workpiece 2 is good or not without erroneous recognition.

  In particular, according to the present embodiment, since the photographing unit 4 and the illumination unit 3 are arranged via the workpiece 2 held by the holding unit 5, the workpiece 2 is based on the workpiece 2 held by the holding unit 5. On the other hand, the photographing unit 4 and the illumination unit 3 are not provided in the same direction (position on the same side). Therefore, the reflected light of the light irradiated on the work 2 (in the direction of the two-dot chain line in FIG. 1) and the reflected light reflected by the holding unit 5 holding the work 2 are not photographed by the photographing unit 4 and are reflected on the work 2. Indeterminate objects including all attached or formed foreign matter (such as scratches, dust and stains) can be found.

  In addition, according to the present embodiment, the photographing unit 4 and the illumination unit 3 are not provided in the same direction (position on the same side) with respect to the work 2 on the basis of the work 2 held by the holding unit 5. The holding unit 5 can be prevented from shining white due to illumination from the illuminating unit 3, and erroneous recognition of the holding unit 5 as an uncertain object including foreign matter due to white light emission can be prevented.

  In addition, a prevention plate 7 that is inclined with respect to the work 2 is provided at a position on the opposite side of the illumination unit 3 that faces the side on which the imaging unit 4 is arranged, and the imaging unit is interposed through the through hole 31. 4 and the prevention plate 7 face each other, so that the light reflected by the work 2 and the holding unit 5 can be prevented from being photographed by the photographing unit 4.

  Further, since the prevention plate 7 is a blackboard, the shooting area (field of view) in the shooting unit 4 can be made black.

  Further, since the light source unit 33 is a plurality of LEDs, the illumination life is long, there is no decrease in output, and stable illumination can be performed.

  In addition, since the photographing unit 4 is intended for photographing light having a wavelength shorter than red, the contour of an uncertain object including a foreign object in a photographed image by the photographing unit 4 becomes ambiguous due to a long wavelength such as red. It is possible to clearly photograph the foreign matter by the photographing unit 4.

  In this embodiment, the foreign matter is discriminated when the major axis is 20 μm or more. Therefore, the foreign matter is discriminated based on the size of the uncertain object including the foreign matter, not by the pixel. Can improve the accuracy.

  Further, since the light source unit 33 irradiates the work 2 held by the holding unit 5 with directional light having an angle, the light from the illumination unit 3 does not directly irradiate the photographing unit 4 and the work 2. Even if light is applied to the workpiece 2, the workpiece 2 itself is not illuminated. Therefore, only when foreign matter exists in the work 2, an uncertain thing including the foreign matter can be illuminated, and the foreign matter can be easily confirmed.

  Further, since the photographing by the photographing unit 4 is monochrome photographing, and the photographing unit 4 is intended for photographing a single wavelength light, it is necessary to clarify the dimensions of an uncertain object including a foreign object even in the case of monochrome photographing. And the equipment cost can be reduced.

  In the present embodiment, the present invention is applied to a filter that is an optical component as the workpiece 2 to be inspected. However, the present invention is not limited to this, and can be inspected by the transmission type inspection apparatus 1 according to the present embodiment. Any other optical component (for example, an optical lens) may be used.

  In the present embodiment, the present invention is applied to a filter that is an optical component as the workpiece 2 to be inspected. However, the present invention is not limited to the optical component, and the inspection is performed in the transmission type inspection apparatus 1 according to the present embodiment. As long as it is possible, other parts (workpieces) such as a quartz wafer used for a quartz oscillator or a package of electronic parts may be used.

  In the present embodiment, the holding unit 5 is provided in the inspection apparatus 1, but the form of the holding unit is not limited to this, and the holding unit 5 is not fixedly provided in the inspection apparatus 1. Also, a holding unit provided in a transport device that transports the workpiece 2 to the inspection device 1 may be used. For example, a system in which the inspection apparatus 1 is provided as one of the manufacturing apparatuses for the work 2 is constructed, and in this system, the work 2 is provided in a transfer apparatus for transferring the work 2 to a plurality of manufacturing apparatuses including the inspection apparatus 1. It may be a holding part. That is, the holding unit 5 that holds the workpiece 2 only needs to be arranged between the illumination unit 3 and the photographing unit 4 so as to be fixed or movable.

  In the present embodiment, the information processing device 6 is connected to the photographing unit 4 by wire. However, the present invention is not limited to this, and the information processing device 6 is wirelessly connected to the photographing unit 4. Also good.

  In this embodiment, a seamless zoom lens is used for the camera as a suitable example in order to enable inspection of the workpiece 2 of various sizes. However, the present invention is not limited to this, and a single-focus lens is used. It may be used.

  In this embodiment, the seamless zoom lens is used in the camera in order to cope with the inspection of the workpiece 2 of various sizes. However, the present invention is not limited to this, and a zoom lens having a preset magnification is simply used. It may be used.

  In this embodiment, a camera that performs monochrome photography is used for the purpose of reducing equipment costs, but the present invention is not limited to this, and a camera that performs color photography may be used.

  In the present embodiment, the holding unit 5 holds the workpiece 2 by pressing the side surface of the workpiece 2. However, the holding unit 5 is not limited to this, and may be a mechanism that can hold and hold the workpiece 2. For example, the outer peripheral side surface of the workpiece 2 may be sandwiched.

  In the present embodiment, a glossy blackboard is used for the prevention plate 7, but the present invention is not limited to this, and is set so that the light reflected by the work 2 and the holding unit 5 is not reflected in the photographing unit 4. For example, a mirror plate may be used as the prevention plate 7 in the dark field environment around the prevention plate 7. In the present embodiment, the prevention plate 7 is disposed at an inclination of about 45 degrees with respect to the holding portion 5 holding the workpiece 2, but is not limited thereto, and the workpiece 2 and the holding portion 5 are not limited thereto. The tilt angle may be set so that the light reflected at is not reflected on the photographing unit 4.

  In the present embodiment, the prevention plate 7 uses a blackboard in which an inclination angle is set so that light reflected by the work 2 and the holding unit 5 is not reflected on the photographing unit 4. The reflected light may be absorbed so that the reflected light is not reflected on the photographing unit 4.

  Further, in this embodiment, the plurality of LEDs are arranged in a plurality of upper and lower two rows, but the arrangement of the LEDs is not limited to this, and is a light source unit 33 having an annular shape in plan view. If the directivity from the LED is set so that the light emitted from the LED does not directly enter the lens of the camera of the photographing unit 4, other forms (other numbers or arrangements) may be used.

  Further, in this embodiment, the illumination unit 3 using LEDs as the light source unit 33 is provided in the inspection apparatus 1, but the light source unit 33 is not limited to this, and for example, a light source as shown in FIG. The illumination unit 3 using halogen for the unit 33 may be used.

  The illumination unit 3 shown in FIG. 3 uses halogen (not shown) that irradiates light to the light source unit 33 using a fiber guide (not shown). Further, in the illumination unit 3, an annular gap 35 is formed in the housing of the illumination unit 3 on the light path for irradiating light from the halogen onto the work 2 through the fiber guide. . In addition, you may provide the diffusion filter 34 shown in FIG. 2 in the illumination part 3 shown in this FIG.

  3 is provided with a filter (not shown) for selecting (filtering) light from the light source unit 33 into light having a shorter wavelength than red on the light path from the gap 35 or the halogen. It has been. In this case, even with a halogen that emits visible light including red, the external shape of the foreign matter can be clarified by selecting the wavelength. Furthermore, it is possible to clearly capture the foreign matter by the photographing unit 4 by suppressing the outline of the foreign matter of the photographed image by the photographing unit 4 from becoming ambiguous (blurred) due to the long wavelength such as red of visible light. it can. In this example, a filter is provided on the light path from the gap 35 or the halogen. However, the installation position of the filter is not limited to this, and may be before the light enters the imaging unit 4. Therefore, a filter may be provided in the photographing unit 4 (for example, immediately before the camera lens).

  It should be noted that the present invention can be implemented in various other forms without departing from the spirit, gist, or main features. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The inspection apparatus according to the present invention can be applied to inspection of optical materials and electronic parts.

FIG. 1 is a schematic configuration diagram illustrating a relationship between the inspection apparatus and the information processing apparatus according to the present embodiment. FIG. 2 is a schematic perspective view of the illumination unit according to the present embodiment. FIG. 3 is a schematic configuration perspective view of an illumination unit according to another example of the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inspection apparatus 2 Workpiece | work 3 Illumination part 31 Through-hole 32 Inner wall surface 33 Light source part 35 Gap | interval 4 Imaging | photography part 5 Holding | maintenance part 6 Information processing apparatus 7 Prevention plate

Claims (10)

In inspection equipment that inspects workpieces to be inspected,
An illumination unit having an annular light source unit for illuminating the workpiece, and a photographing unit for photographing the workpiece;
A holding unit for holding the workpiece is arranged between the illumination unit and the photographing unit so as to be fixed or movable,
The photographing unit is arranged at a position deviating from the irradiation direction of the light irradiated to the work from the light source unit of the illumination unit,
When there is an uncertain object including a foreign object in the workpiece, the light irradiated to the workpiece from the light source unit is photographed by the imaging unit with its optical path changed by the uncertain object including the foreign object. Inspection device to do. The inspection apparatus according to claim 1,
The inspection apparatus is intended for imaging light having a wavelength shorter than red. The inspection apparatus according to claim 1 or 2,
An inspection apparatus characterized in that when an uncertain object is present in a workpiece and the uncertain object has a major axis of 20 μm or more, the uncertain object is determined as a foreign object. In the inspection apparatus according to any one of claims 1 to 3,
The said light source part irradiates the directional light which has an angle with respect to the workpiece | work hold | maintained at the said holding | maintenance part. In the inspection apparatus according to any one of claims 1 to 4,
The illumination part is composed of a cylindrical body having a through hole,
A prevention plate disposed at an inclination with respect to the workpiece is provided at a position on the opposite side of the illumination unit opposite to the side on which the photographing unit is disposed,
The inspection apparatus, wherein the imaging unit and the prevention plate face each other through the through hole. The inspection apparatus according to claim 5, wherein
The inspection apparatus, wherein the prevention plate is a blackboard. The inspection apparatus according to any one of claims 1 to 6,
Shooting by the shooting unit is monochrome shooting,
The imaging unit is intended for imaging single-wavelength light. In the inspection apparatus according to any one of claims 1 to 7,
The said light source part consists of LED, The inspection apparatus characterized by the above-mentioned. In the inspection apparatus according to any one of claims 1 to 7,
The light source unit is made of halogen,
An inspection apparatus, wherein a filter for selecting light from the light source into light having a wavelength shorter than red is provided in at least one of the illumination unit and the imaging unit. The inspection apparatus according to any one of claims 1 to 9,
The inspection apparatus according to claim 1, wherein the illumination unit includes a diffusion filter that diffuses light irradiation in front of a light irradiation direction of the light emitted from the light source unit.

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